🔵 Movement Profile (pitcher POV)
📊 Pitch Usage & Shape
📋 Arsenal Summary Table
🟠 Aggregate Scores
Per-Pitch Stuff+ / Location+ / Pitching+
🔵 Pitch Movement Profile
🟢 Exit Velo vs. Launch Angle (Batted Ball Profile)
📊 Quality Zones
📋 Batted Ball Summary
🟡 Swing Heat Map (all pitches)
🟡 Whiff Map (swings only)
📋 Plate Discipline Metrics
📊 Composite Pitcher Score (CPS) — Weight Calibration
Adjust weights (must sum to 100%)

                  
                

                
              

            

            

              

                
📊 Composite Hitter Score (CHS) — Weight Calibration

                

                  
Adjust weights (must sum to 100%)

                  

                  

                  

                  
                

                
              

            

          
        

        

          

            

              

                
MLB Leaderboard

                

                  

                

                
              

            

            
            
            
          

        

        

          

            

              
            

            

              

                
Data Sources


Baseball Savant (Statcast)



FanGraphs (Stuff+ / Location+ / Pitching+)


    

  • R function: baseballr::fg_pitcher_leaders(type=36) — type 36 = Stuff+ leaderboard
    • 

  • Fields: Stuff+, Location+, Pitching+, CSW%, Whiff%, xFIP
    • 

  • Note: Requires FanGraphs leaderboard access; no API key needed for public data
    • 



PitchingNinja Grades


    

  • Source: Manual input from @PitchingNinja (Rob Friedman) public grades
    • 

  • Integration: Enter in yellow cells in 🟠 STUFF_PLUS sheet or Shiny grade form
    • 



Chadwick Bureau Player ID Crosswalk


    

  • R function: baseballr::playerid_lookup() — resolves name → MLBAM + FG IDs
    • 

  • Required: To join Statcast (MLBAM IDs) with FanGraphs (FG IDs)
    • 




              

              

                
Stuff+ / Location+ / Pitching+ Primer


What is Stuff+?


Stuff+ quantifies pitch nastiness independent of location and outcomes.
A score of 100 = MLB average. 120 = very good. 140+ = elite.


Inputs (FanGraphs Model — Eno Sarris, 2023+)


    

  • Release velocity
    • 

  • Induced Vertical Break (iVB = pfx_z × 12, pitcher perspective)
    • 

  • Horizontal Break (HB = pfx_x × 12)
    • 

  • Spin rate (RPM)
    • 

  • Spin axis
    • 

  • Release extension
    • 

  • Velocity differential vs. primary fastball
    • 

  • iVB differential vs. primary fastball
    • 



Location+


Measures how well a pitcher places their pitches — independent of stuff quality.
100 = average. > 100 = above-average command.


Pitching+


Combined model: Pitching+ ≈ f(Stuff+, Location+). Best single-number pitcher quality metric.


PitchingNinja Integration


Rob Friedman’s grades are qualitative but highly predictive of future whiff rates.
Scale: 0–100. Elite ≥ 90. Input manually in the Shiny app grade form.


R Data Pull


library(baseballr)
# Stuff+ leaderboard (type=36)
stuff_df <- fg_pitcher_leaders(startseason=2024, endseason=2024, type=36, qual=0)
head(stuff_df[, c('PlayerName','Team','IP','Stuff+','Location+','Pitching+')])




              

              

                
Model Methodology


Composite Pitcher Score (CPS)


Weighted combination of 9 metrics, each normalized to 0–100 via MLB percentile rank.






Metric
Default Weight
Direction






CSW%
20%
Higher ↑




Whiff%
15%
Higher ↑




xBA Against
15%
Lower ↓




Avg Velocity
10%
Higher ↑




Extension
5%
Higher ↑




Spin Rate
10%
Higher ↑




Stuff+ (FG)
15%
Higher ↑




Location+ (FG)
5%
Higher ↑




PN Score
5%
Higher ↑






Composite Hitter Score (CHS)






Metric
Default Weight
Direction






xwOBA
35%
Higher ↑




Barrel%
20%
Higher ↑




Avg Exit Velo
15%
Higher ↑




Hard Hit%
15%
Higher ↑




Discipline
10%
Higher ↑




Sprint Speed
5%
Higher ↑






Validation


CPS is benchmarked against FIP-, xFIP-, SIERA.
CHS is benchmarked against wRC+, OPS+, DRC+.



              

              

                
R Code Snippets


Load a pitcher’s Statcast data


library(baseballr)
# Look up player ID
gerrit <- playerid_lookup('Cole', 'Gerrit')
mlbam  <- gerrit$key_mlbam[1]

# Pull pitch-level Statcast data
sc <- statcast_search_pitchers(
  start_date = '2024-03-01',
  end_date   = '2024-09-30',
  pitcherid  = mlbam
)



Calculate Stuff+ inputs


library(tidyverse)
arsenal <- sc |>
  filter(!is.na(pitch_type)) |>
  group_by(pitch_type) |>
  summarise(
    n        = n(),
    usage    = n() / nrow(sc),
    avg_velo = mean(release_speed, na.rm=TRUE),
    avg_spin = mean(release_spin_rate, na.rm=TRUE),
    ivb      = mean(pfx_z * 12, na.rm=TRUE),   # inches, pitcher POV
    hb       = mean(pfx_x * 12, na.rm=TRUE),   # inches, pitcher POV
    avg_ext  = mean(release_extension, na.rm=TRUE),
    whiff_pct = sum(description %in% c('swinging_strike','swinging_strike_blocked')) /
                sum(description %in% c('swinging_strike','swinging_strike_blocked',
                                       'foul','hit_into_play')),
    csw_pct  = sum(description %in% c('called_strike','swinging_strike',
                                      'swinging_strike_blocked')) / n()
  )



Pull FanGraphs Stuff+ (type=36)


stuff_lb <- fg_pitcher_leaders(
  startseason = 2024, endseason = 2024,
  type = 36,   # <-- key: Stuff+ / Location+ / Pitching+ tab
  qual = 20    # min 20 IP
)
stuff_lb |> select(PlayerName, Team, IP, `Stuff+`, `Location+`, `Pitching+`) |> head()



Run CPS model


source('R/utils_calc.R')
weights <- readRDS('data/weights_default.rds')

stuff_data <- stuff_lb |> filter(playerid == gerrit$key_fangraphs[1])
cps <- calc_cps(sc, stuff_data, weights$cps)
cat('CPS:', cps$cps_raw, '|', cps$grade)